Utter dissapointment

A few friends and I went out to celebrate a birthday,at the door we asked how old we are,we're all adults but just mall built,and we've been there many times before and no I'd's were asked.During the course of the night we had to leave our table go to the bar and ask for service,whilst the waiters were chatting away...they had a Savanna promotion where you get 4 ciders for R90 which we took upon,only to come find billing time it was R220 the shock we were faced with! We asked to see the manager 2 guys presented themselves and none of them were the manager,security was called in but to no avail..we told them we not refusing to pay but we will not pay for something we did not order! 2 waiters sold one promotion to us and the one told the 'manager' that they had indeed done so but he would not listen to reason...we ended up paying because it looked like we were the fools...I don't like that they think beacuse your had a few drinks they can take advantage of you as a customer! Bad customer service! Bad attitute! *********** 'managers'! False promotion! Incorrect billing!