Regain data from iphone 6s(not sure if plus) factory reset? Sorry if this is not the right place to ask this, but I'm not sure of anywhere else I can post this.

Some time ago I changed my iPhone(iPhone 6s or 6s plus, not sure which, should be latest ios, 12 at the least.) password, but now I forgot and I have tried until I reached the 'iPhone is disabled, connect to itunes' page. I have went to the apple service providers with Proof of Purchase and they said my only option is to restore my iPhone, which will wipe out all my data. I was also told the same by a data recovery specialist I was recommended to try by said provider. Is there any alternative? Can I factory reset my phone and try to find the original files using some other third party data recoverer or is factory reset the same as restore and will also overwrite the data?

I know the files will be likely to be encrypted and take a long time to decrypt, if not forever. That is fine, as long as I can extract the files, encrypted or not I am ok with their status.
If you have not done a backup either to iTunes or to iCloud, then there aren't any ways to do retrieve that information. It is an Apple security mechanism. Hypothetically, let's say someone stole your phone, tried to guess your password over and over, it would disable it. There are programs to access a lower level of the phone, but they require it to be unlocked. The only thing I can think of is using major data recovery, like through DriveSavers or Kroll Ontrack recovery services. They're quite expensive though. It'd recommend attempting to restore from your most recent iCloud backup. It won't hurt. 

Unfortunately, if that doesn't work, you will have to restore your phone, and there won't be a way to get that information back.