FIDO screws me out of $50

My mobile phone company lied to me! I signed an agreement last month to keep my $40 cityfido plan and got the Sony Ericsson z600 at the same time for $200. Then prior to my 14 return period I see that the fido store in Metrotown had a $50 additional bonus off a handset with contract. I call into customer service and ask them for this credit. The girl on the other line said that she will credit me the money.

Today my bill arrives and guess what? No credit. I call in and the CSR says that there's no comments on my account about a credit so they can't do anything about it!I was actually debating whether to change to the Motorola V400 or keep the z600 during my 14 day return period, but seeing that I could get the z600 for $150 sealed the deal. Now I feel like they just told me they would credit me so that I would stay past the return period and have me locked into their contract!!!I'm totally pissed. I asked to speak to a supervisor, but they said he can't take my call right now but he will call me back within two business days.

Why did that stupid CSR tell me she would credit me in the first place?! Why didn't she make a comment on my account!? This sucks!