Will EE sort this out? code 012, apple ultra, mobile plan.

I purchased a cert refurbed Ultra (generation 1) from Apple Store, hoping to go cellular with my current EE mobile plan. Upon setting up, code 012 appeared saying I needed to call EE. Spoke with 4 level 1 and 2 techs who could not figure it out. A lot of resetting devices and going through the device set up many times. I was told that if I had of purchased the device from EE this would not of happened, the EE rep blaming Apple (all pathways with EE lead to "buy another device through us" or " add another plan, spend more money".

The issue was escalated but they could not give me a call back time. After missed calls I arranged a call back time, but the rep told me he "Had to go searching for the person in the office to do this".

Speaking with the upper level tech, the following day, she told me code 012 happens ALL THE TIME, in fact her entire weeks work is manually adding Apple and Samsung watches to plans as the code EE uses gets confused when a customer has more than one account/an email address associated with an account. Sorted it out for me in 5 minutes. All up and running, and running well. Apple were great, they supported throughout but did suspect mobile carrier were at fault, even sent me reading materials to explain some issues known to be experienced previously.

Will EE sort themselves out and stop blaming other companies for an advertised premium service that they struggle to provide! In this case the problem was that I had too many accounts with EE....this is not a good way of encouraging people to send more business their way.

Any opinions?