Intro
Ahmadis are the biggest liars in the world.  Their deception and open lying came directly from Mirza Ghulam Ahmad and his greediness.  In the case of prophethood.  MGA denied being a prophet in 1891, as he claimed to be the Messiah and a strange type of Mahdi.  Interestingly enough, in this era, MGA also wrote that many Mahdi’s and Messiahs could come.  MGA was purposely deceptive and figurative, his real intention was to claim prophethood, however, he seemed to be afraid of getting killed, so initially, in 1891, he denied prophethood and then continued to deny it for 10 years. However, the ulema of India didnt believe MGA and published a Fatwa of Kufr, they cited that MGA was describing himself as a prophet, and then denying the obvious.  

Nowadays
Ahmadis will find people on the internet and real-life who don’t know the ins and outs of Ahmadiyya lies.  They will quote 4:69 and other verses and then argue that Allah can send a prophet whenever he wishes, they will never mention MGA’s 10-year denial of prophethood and subsequent about-face.  However, the other point that they miss is that 33:40 supersedes all other verses on prophethood and thus ends this system of sent prophets from Allah.

The Quran only mentions “independent-prophets”
The Quran rarely ever mentions different types of prophets, the only additional distinction is that of “Rasul”, which allah only named a few prophets as such, this word seems to only be used in terms of a word of endearment, nothing else.  The Quran never says that Muhammad (saw) can help someone become a prophet, this is false, only Allah makes prophets, hence they are independent.  In Nov. 1901, MGA claimed prophethood, however, he claimed that his prophethood was not-independent, in other words, devotion and love for Muhammad (saw) helped MGA increase in rank and finally be regarded as a prophet.

Muhammad is prophet number #124,000
There is a famous hadith wherein the total number of prophets is stated at 124,000.  Ahmadis dont understand this hadith.  And it seems to be a low-level-authentic hadith.  I have reproduced some data here:

It was narrated that Abu Dharr said: I said: O Messenger of Allah, how many Prophets were there? He said: “One hundred and twenty four thousand.” I said: O Messenger of Allah, how many of them were Messengers? He said: “Three hundred and thirteen, a good number.” I said: O Messenger of Allah, who was the first of them? He said: “Adam.” … 

Narrated by Ibn Hibbaan, 361 

This hadeeth is da‘eef jiddan (very weak). Its isnaad includes Ibraaheem ibn Hishaam al-Ghassaani, of whom adh-Dhahabi said: he is matrook (rejected). Indeed, Abu Haatim said: (He is) a liar. Hence Ibn al-Jawzi ruled that the hadeeth was fabricated and false. 

Ibn Katheer (may Allah have mercy on him) said:  

This hadeeth was narrated at length by al-Haafiz Abu Haatim ibn Hibbaan al-Basti in his book al-Anwaa‘ wa’t-Taqaaseem, and he said that it was saheeh. But Abu’l-Faraj ibn al-Jazwi disagreed with him and included this hadeeth in his book al-Mawdoo‘aat (the fabricated hadeeths) and accused Ibraaheem ibn Hishaam of fabricating the hadeeth. There is no doubt that more than one of the imams of al-jarh wa’t-ta‘deel (evaluation of hadeeth narrators) criticised him because of this hadeeth. 

Tafseer Ibn Katheer, 2/470 

Shu‘ayb al-Arna’oot said: Its isnaad is da‘eef jiddan (very weak) – and he quoted the comments of the scholars about Ibraaheem ibn Hishaam.

Tahqeeq Saheeh Ibn Hibbaan, 2/79 

2.

A hadeeth mentioning this number – one hundred and twenty four thousand – was also narrated via another isnaad: 

It was narrated that Abu Umaamah said: I said: O Prophet of Allah, how many Prophets were there? He said: “One hundred and twenty four thousand, of whom three hundred and fifteen were a good number.” 

Narrated by Ibn Hibbaan in his Tafseer, 963 

Ibn Katheer (may Allah have mercy on him) said: 

Mu‘aan ibn Rifaa‘ah as-Silaami is da‘eef; ‘Ali ibn Yazeed is da‘eef; and al-Qaasim Abu ‘Abd ar-Rahmaan is also da‘eef. 

Tafseer Ibn Katheer, 2/470

Ahmadis argue endlessly on the continuation of prophethood
This evidence proves that NO new prophets will ever be born, Esa (As) will return, however, he is prophet #123,999, so 33:40 is still valid, and all the Ahmadi arguments have collapsed.