V60t driving me nuts, is it the phone or service

I owned an analog only phone for years and although I may of got lots
of static I did not lose the connection and could get through the
call.

I expected I could force my new v60t into analog mode if I was not
happy with digital performance and I'm not. It sucks. And I can't
force it into analog mode.

I live in greater Boston area and I cannot use this while driving. It
is incapable of switching antennas live.

Example:

5 bars going down mass pike, talk. 4 bars, 3 bars, 2 bars disconnect,
instantly 5 bars comes back. Call again 5, 4, 3, 2, disconnect,
instantly get 5 bars again.

This phone is so unreliable I'm ready to chuck it and not have a phone
at all.

I like everything else about the phone.

This is att service.

Can I put a better antenna on it?

Phone is still under warranty, should I bother trying another.

I think it's just that digital sucks. My friend has had numerous
phones and his sucks too.