Chosen Solution
Around a year ago I smashed my first iPhone so I took it to a store to be repaired, afterwards it was working fine but then the screen started to come up but it went down when pushed back in, it then started to have charging problems and wouldn’t turn on at all, I really need it to work if possible, last resort I buy a new phone… thank you.
From your description, it sounds like the battery is swelling. That would explain the screen being pushed up and the charging problems. I would open up the device and take a look. If the battery looks like a bag of chips, then it definitely needs replacing. To be certain, use a battery utility, such as coconutBattery (for Mac) or 3uTools (for Windows). It will tell you what the health of the battery is. Anything less than 80% of design capacity will require replacement. Be wary of cheap replacement batteries and order from a reputable vendor. Take a look at this guide to see what is involved before attempting this repair yourself.
Have you tried the basics 1st? Try cleaning out the charging socket in the bottom of the phone they can get fluff, dirt, bits etc stuck in the bottom which stops the charging plug going all the way in.
