Legal assistance with subscription problems

Questioner

today I wanted to take out a phone subscription the employee was clearly not handy in this at the last after all copies of my ID and he was unable to get the subscription with the associated telephone through after several attempts, he pushed it through manually, as he called it then a strange message came The customer you just entered has been accepted but can only be activated with a limited number of combinations of price plan and device payments This message was printed out and I was referred by MediaMarkt to show the letter in a T-Mobile store, because the salesperson had never seen this before now comes the next thing when I got home I saw a signed document from the media market 3 times 2x a contract subscription with telephone and as a 3rd a separate subscription without telephone I think the last one is the contract that the strange message was about I now think that the first 2 attempts were simply approved, the results of which were probably not seen due to the impatience of the employee. and that T-Mobile thought after the 3rd contract, we are not going to give away a 3rd phone.... So on paper I am now actually stuck with 3 subscriptions and 2 phones the employee is wrong and will have to cancel 2 contracts However, the question is whether they are just as much stuck as I am to the signed document? And whether they should continue with the subscription that is apparently already in effect according to the contract and therefore also hand me over 1 associated mobile phone? and how can they give me legally valid proof that at least 2 of the 3 signed documents have been nullified so that I do not subsequently receive 3 times the subscription costs for which I have not even received 1 of the associated mobile phones By the way, I only signed once on the employee's tablet-like device

Lawyer

It is the seller who has to solve this for you because their employee has been bungling. Obvious mistakes so two contracts are not valid,