Windows 7: How do I recover unallocated hd partition?

If changing a drive to a different SATA port would void whatever warranty you think you have then you need to find a new tech to take your system to.
In the first place a warranty is useless except for component failure. It never covers software, user error in software or basically anything else.
In fact the component manufacture has probably a better warranty on there components then what this repair shop has given you. The only time that isn't true is with major system builders like Dell, HP and the like. No matter what parts are used in there systems the original manufacturer of those parts put all warranty claims back on the system builder becasue in the most part all those part are specifically made to the system builder specs and sold to them at a lower cost in bulk then anyone can buy them for.

You've probably already voided the warranty by taking the case cover off.
Maybe it's time to start doing your own work instead of taking the system to a repair shop.
All they do is replace pre-made parts. It not like they take those parts apart and fix a bad component inside those parts.
In fact the repair shop you took your system to F it up by not placing the SSD on SATA port 0. My god how dumb/uncarrying/unknowing are they not to place a SSD that you're going to use as the OS BOOT drive on some other port then the first one in the system.