An ITunes Restore Issue for IPhone 8

Having just upgraded to an IPhone 8 I started restoring from ICloud only to be faced with a request for a password to an old ITunes account which not only has not been used for many years, but the name does not include an email address in it's account title. As a result, constant messages appear on the IPhone which cannot be resolved and will not go away without switching the new phone off and starting again. I have not used many passwords from so long ago, but none are accepted and when responding to the usual forgotten login details, the reply appears along the lines that this isn't really an ITunes account as it doesn't contain an email address as account name.

I know this problem has appeared before but I cannot see how Apple has taken action to resolve a basic error problem with old ITunes accounts not being in email account name format.

In short, how can I stop the messages appearing and actually delete the account or succeed to change the account name and then successfully restore old purchases?

Help is needed please!