Does your executive committee have a treasurer or is all delegated to the strata manager? In any case, a question you could put to the EC is “What do the OC records show of my arrears?”
As treasurer of our OC, if an owner asked me about his or her arrears, I would be able to quickly give an answer of what the managing agent’s records show – I can access the unit balance list electronically. If the amount was not what you thought, then I would strongly recommend taking that specific point up with the managing agent. They should be able to reconcile their records with your receipts.