Total disregard for customer needs

I have been using The Courier Guy for some time how ever their service has gone down the toilet and the shockingly poor attempt at migrating to a new booking system is a big fail, All my historical records and the whole address book is gone. Customer had not for warning of a system change either. I enquired about this only to be told that they chose not to migrate the data. I work in the IT industry and if I ran a migration project like this I would be out of a job. They are also unwilling to assist.