Is this £55 worth the effort?

Natwest owe me it. Last year they were offering incentives for signing up for a student account - a young person's railcard, or £55. At the time, you had to be under 27 to use a young person's railcard so I was way off being eligible. The rules have changed now and I would be eligible, but I hardly ever use the train so I wouldn't want one anyway. I don't actually need a student account but I'm not one to turn down free money.

I opened the account in November and made the first payment in February when I started the course, as I had read somewhere on a piece of paper that I can no longer find, that something like £500 had to be paid in before they would cough up. Studying then filled my brain leaving little room for anything else and when the holidays came around I realised my £55 had never been paid.

I phoned the branch and explained. They told me to phone the people who dealt with student accounts. I phoned the people who dealt with student accounts and they told me to phone my branch. You can see where this is going, can't you. I rang the branch number and was told I was speaking to 'branch support' (aka a call centre, presumably) and they would get someone from my branch to call me. Surprise, surprise - I never got called back. Now my 'holiday' is over I called the branch again and, miracles will never cease, I actually spoke to someone in the branch! However, he told me I would need to write to the branch manager so he/she could sort it out as it's been a long time and the branch people can't remember if they were offering money at the time or not.

I can't decide if I'm being tight and should let it drop or if I should pursue it because it's mine by rights. On the one hand £55 isn't that much, it's only the cost of getting my car trim sorted out. On the other hand, £55 is a lot of money, I could get a couple of text books for that. Or alternatively, just think of all the Lush I could buy for £55! Stupidly, I feel a bit guilty as I'm not really using the account, i.e. I'm not running up huge overdrafts on it.

However there is another £69 which is definitely worth chasing - the NHS student grants people have underpaid me my travel expenses. Why is nothing ever easy?