I haven't run across many cases of the Sieve code "not working". It's usually a case of an unrecognized interaction where another rule is being applied to the message rather than the one you think should apply.
My
sieve tester is a good way to do some diagnostic testing .. copy an email which didn't get filtered like you wanted into the bottom box and your current sieve script into the top box. Run the test .. and if that reveals the end result is that the message is being filtered to an undesired folder/action, remove a chunk of sieve code and try again. You should be able to quickly narrow down to the piece of sieve code which is causing your problem and then you can tweak the filter to pass the message through in the future (or just rearrange your code so that the problem rule comes after the cellphone redirect).