I can understand people paying a relatively large amount of money wanting as much comfort as possible, but when booking the flights your carrier will be specified, and whilst I personally don't think there is a major problem with TOM's seat pitch, why would one expect a Charter carrier to have anything other than relatively limited seat pitch versus mainline sched carriers.
The name of the charter game is the more seats on board an A/C the more holiday revenue can be generated, I am quite sure that your travel agent, even a Thomson one can 'de-package' and book you on a more spacious carrier at twice the cost, failing that sit back enjoy the flight and have a great time.
To be frank, and we can all be guilty of this including myself at times, if we haven't got something to moan about, we would moan about having nothing to moan about