Yes. Phone support is only for Broadband customers, and even then only for broadband issues.
Did you try the Live Chat? It works very well, apart from a rather distressing tendency to hang up on you if it (erroneously) thinks you aren’t there any more.
Re the three Passes, did you buy a NowTV stick with three ‘free’ passes on it, but only watched on one of them?
NowTV will have activated all the passes at once, likely. I expect it’s in the small print somewhere that that happens.
Or was it in some other circumstances?
Set a Payment PIN on your account so that no-one but you can buy memberships on it. Check your bank accounts monthly for any other unexpected payments to Now. That way you can at least nip them in the bud, while you and Now figure out whose fault they are.