7:52 doesn't say anything of the sort.
"We have given them
the Book; We have spelled it out knowingly as a guideline and mercy for folk who believe.
Do they look for (anything) except its interpretation? The
Day its interpretation comes up, the ones who forgot it earlier will say, "The Messengers of Our Lord already came with the Truth; so, have we any intercessors, (for) then they would intercede for us, or will we be turned back to do other than what we were doing?" They have already lost their (own) selves, and what they were fabricating has erred away from them"
7:52-53 (Translated by Muhammad Mahmoud Ghali)
So, according to this verse, its interpretation comes, then those people who understand its true interpretation, would realize what Quran has promised is true.
Some translators, say, its fulfilment comes (instead of interpretation). That is also a correct and possible translation.
See, the point is, in verse 3:7, it says, some verses are metaphorical and only God knows their interpretation. So, a valid question is, what is the point of Book of God having verses that only God knows its interpretation. Well, a good answer is, verse 7:53, where it promises that its interpretation will be given in its own time.
There are many, detailed, specific descriptions of the tortures of hell. Are you claiming that every one of those is metaphorical and that there is not painful punishment for those who reject Islam?
If so, what was the purpose of those lurid descriptions of the torments of Jahannam?
Yes, because if all those event were literally to happen, how come the Quran says, even after the Day of Judgement comes people are still unaware of it:
"And warn them, [O Muhammad], of the Day of Regret,
when the matter will be concluded; and [yet], they are in [a state of] heedlessness, and they do not believe." 19:39
See, even after the Day of Judgement comes they are still heedless and do not believe. This tells us, the signs of Day of Judgement are not to be interpreted literally, because if literally the stars fall or darkens, heaven is opened, and Fire of Hell appears, then surely all people will see it and believe.
But each of these have a symbolic meaning. Just like, for example when a man saw in a dream 7 fat cows and 7 skinny cows, its fulfilment was literally 7 cows.. but these cows represented years. (See story of Joseph in 12 th surrah of Quran, or the Old Testament).
So Judgement Day was 400 years ago?
"And they ask you to hasten the punishment. But never will fail Allah (in) His Promise. And indeed, a day with your Lord (is) like a thousand year(s) of what you count" 22:47
So, this verse is alluding that the Judgement Day comes in a 1000 years.
The question is, from when, the 1000 years period is to be counted. The following verse tells us:
"He directeth the ordinance from the heaven unto the earth; then it ascendeth unto Him in a Day, whereof the measure is a thousand years of that ye reckon" 32:5
This verse tells us, first God directs the ordinances from Heaven to earth. Once this is done, then 1000 years after, the Judgement Comes.
The flow of guidance according to Shia tradition continued after Quran, through the Imams. The 11th Imams passed away in year 260 AH. That means the ordinances were directed till year 260AH. So, if you add 1000 years, it comes to the year 1260 AH, in Islamic calander, which is 1844 in Christian calender.