Programming issues with Icom F21

Question

I recently purchased 2 2-ch Icom F21 portable 2-way radio's. I was hoping that they would communicate with 2 other 16-ch I-com F21's my husband had. We went through all the channel combinations and the radios will not communicate with one another. I am assuming this is a programming issue, but I was wondering if there was anything else I can do with out sending them all back to the dealer.