Don't panic! Getting upgrades through the system can take a few months, although recently the BMMC's part of the job has been done very quickly (cheque to the usual address, Simon!
) : the MSA takes longer, partly because of the requirements of the grading system.
Looking at your profile, I assume the upgrade your are waiting for is trainee to course? This may well take longer than other upgrades, as in addition to the normal upgrade procedure the MSA will have to create an identity for you. For attendance signatures, you can carry on using your 'trainee' MSA card (the green one).
As for missing upgrade signatures, don't worry. In fact, I'd advise you to do a dozen or so meetings without putting your card for upgrade signatures. Just enjoy your marshalling without the pressure of 'needing' a signature - upgrading's not a race!