Bad Customer Service by the manager

I order a ****tail which came back too sweet and asked the waiter to take it back as it took away my appetite and gave me a headache. The floor manager brought it back after waiting which seamed forever and I told him I didn't want it anymore. My bill came with the ****tail included and when I asked about it the store manager was called whom he asked of what happened and after explaining the story he told me that it was not his fault and he would not in counter a loss because of me I should pay for the bill as his staff told him I drank half of the drink that's when I told him to look at his cameras and if he found that that was not true as I only took 2 sips I wouldn't't pay for the whole bill he recant his story and asked that I only pay for the food eaten. I feel like all he could have done was to get both side of the story before he came and accused me in front of all the people in the store of laying and caused me a seen. I used to brag about Parrots to my friend as I usually eat there on Saturday's after races or going to the gym but if this is the service one gets after a complaint then I don't know. Wonder what does the head office have to say about this??????