How to escalate this issue - bad customer service

We moved from T-Mobile to Xfinity last week, and we are very disappointed with Xfinity's customer service. We visited the Xfinity store in Redmond, WA, where Kevin was assisting us. Once we signed up for Xfinity, we discovered several hidden charges, such as an activation fee. There was a lack of transparency in his communication.

We also wanted to upgrade our devices since we were signing a two-year contract. However, Kevin ported our number before addressing anything related to the upgrades. As a result, he did not upgrade my daughter's device because he ported her phone number first. When we spoke to his manager, we found that they were also unhelpful. In the end, we are left without my daughter's phone and stuck with a two-year contract.

I am not sure why we are facing issues due to Kevin's mistakes, and no one at the store seems willing to resolve this issue. We are very disappointed with this customer service. I would like to escalate this issue and resolve it as soon as possible.