Mango's service is pathetic

I have a flight booked for 13:40 today and I'd like to make changes. I've been calling the call centre from 8 this morning and I eventually called the head office who informed me that the call centre had a problem yesterday but she'll put me through to the same call centre and said hopefully I'll get through this time, which off course I didn't. I called the head office again and this time I was put on hold only to be transferred to the call centre again where off course no one picked up. I even emailed Mango an hour ago and still don't have a response. I'm highly frustrated and no one seems to have the knowledge to help him. Pathetic service.