TAKEALOT cheats

After upgrading my I pad all my purchased e-book titles appeared in the TAKEALOT reader, but 16 cannot be downloaded again. Takealot requires order numbers from me for those titles, which have been bought over the past 7 years. I requested they check their archives, but they did not respond. Surely the fact that the titles appear in the “purchased” file on the reader is prove that I have bought it. According to TAKEALOT the problem is due to publisher restrictons. I also have a library in AMAZON, where all the titles downloaded without any problem. I find the explanation very unsatisfactory. Does TAKEALOT sell e-books, or just the opportunity to read a book? Or do they sell the copyright bought by one person also to others? They are good at sending e-mails with explanations, but don’t expect to talk to anyone, nor that your problem will be resolved.