You know, I'm sure nobody really cares but the usage in AT&T's automated text message isn't really right, but the problem isn't with the word 'receipt'. When people have trouble with usage in compound subjects or objects I advise them to use the words individually to figure out which construction is correct. Works great with 'me' and 'I', when people can't figure it out otherwise. I have no problem with "unlimited receipt of text...", but nobody would say "unlimited send of text...". AT&T probably should have used the gerund (verbal noun) "sending".
There, I said it.