Oh dear!
What are you charging at the moment? There are several topics on this board giving advice on costings. Have you actually got a contract with this Company? How long have you been cleaning for them? Profit is not usually made in the first instance of a contract it is the long term commitment you need from the company, your overheads will drop and that's when you start making money. Do you think they would be happy to re negotiate the price?
PM me with your costings if you like and I will have a look for you. It may be just as well to cut your losses and run! Have you invested in machinery for this contract? Pricing for a commercial contract is completely different than domestic as you probably now realise. I am sorry to hear you have been misled but if you intend to branch out into commercial you now have a very valuable experience to look upon.
Fox