The advice is simple: make repairs at a service center, not at a private owner! And even more so not on the market! Service centers (unless of course they opened yesterday and closed tomorrow) bear responsibility and warranty obligations for repairs. I agree with Roman: pay attention to the place where the service center is located! The room under the stairs of the shopping center should alert you)
And change the module, not just the glass. The novel is right again - few craftsmen can perform touchscreen plywood efficiently. Devices are often brought to us at Samodelkin after such repairs: the edge of the display begins to peel off.
You need to look on the Internet how much the screens for an iPhone in your city cost on average, then deduct this amount from the prices offered for repairs, thereby you can find out how much the master takes for the work. Check reviews and popularity, as well as workspace and service organization. Do not choose the cheapest options with craftsmen who repair right at the point on the knees behind the curtain. There are exceptions though.
this is not a very difficult job, the only thing you need to pay attention to is that the place you are contacting is not in a dirty dusty basement. in this case, the work will be done, but not qualitatively - there will be dust between the matrix and the glass