How can I get my Uniden tru348 handset to re-connect to the base?

Can anyone tell me how to get this phone (uniden tru348) to re-connect to the base unit ?

I did what it said in the manual, and what the customer service person said to do, but it didn't work, and this phone is not in production anymore, so they cannot send me a new one.

I just love this phone, and would rather not get a different make/model from the thrift store, since I cannot afford a new one.

I'd appreciate any ideas !!!