Disgusting service, off food

We went as a group on the 3rd of February to the Portuguese islands. Besides the fact that we all got food poisoning and sick for day, they also messed up my account. They managed to link a strangers room to my account and then proceeded to take over R12000.00 off my account. I was refunded a portion but I have now called and emailed numerous times to get a statement on my account as I was still overcharged. They do not reply to my mails and when I call I get told someone will get back to me.