Changing a battery on my Iphone 4S is too difficult

I bought a new battery for my year and half old Iphone 4S.

In addition to the battery I bought proper tools to do it myself.

Everything seemed to work well, except for a little difficulty taking out the original battery that was glued into place.

I thought I had done everything right but when I restarted the IPhone 4S I was getting the message: "Searching..." The phone turned on and I could use everything, including wireless, but no connectivity to the AT&T network.

Seems other IPhone 4/4S users have encountered similar problems when I did a search on the internet.

I already went to the ATT store and they tried a working SIM card. No luck.

Tomorrow I try the Apple store and if no continual luck I'll try a repair shop.

I think I'm sick of Apple not having user friendly replaceable parts like a battery.

Update >>>

Went to the Apple Store Saturday morning before the opened and they couldn't help me. They asked me to reset the phone completely and restart and they took the phone in back to open it up briefly. They couldn't see anything wrong.

Second, I went to the ATT Store to see about early replacement. They couldn't offer me an upgrade deal until September 1st

Third, I went to a local repair shop: "Bouder Mac Repair," and paid $40.00 for diagnostics and a possible fix. Unfortunately, I shelled out $40.00 and no luck.

Saturday evening I posted the Iphone on cragistlist. Got some bites and sold the phone on Sunday for $150.00. They guy I sold it to works for ATT so I'll presume he had an easy way to fix.

Now using Google voice with my ATT phone number forwarded to it.