Why the domain has not been renewed with the transfer but it has been charged?
Please, be aware this is in general common for gTLDs, like .com , .net, .org domain names.
If you have been charged for a transfer, you can be sure that the domain has been renewed by Openprovider. If you realize that the expiration date is not added with an other year, in most cases, this is the explanation:
At the moment of transfer, domain was in autoRenewPeriod at old registrar. According to ICANN policy, for domains transferred during the auto-renew period, renewal is credited to the losing registrar, and gaining registrar (Openprovider) is charged for it.
If old registrar charged you for this renewal, you need to ask them for a refund, as the registrar should've received the money back from the registry.