Seasonal service

I went into the xfinity office in Ocean City MD to request to be placed on seasonal hold internet access (29.99).  I told the agent that I tried to do it online but it only offered the eight dollar email only plan and he told me that you can’t do it online for Internet but he could set it up for me. Now I find out that he set me up for the email only access and I have tried to get this corrected with Xfinity but they tell me I’m not eligible for the Internet access plan because I have an Internet only plan with 200mbps.  at no time  Did any employees tell me that I’m not eligible for seasonal service with an Internet only plan.  I’m not even sure that’s true. I think the system is not letting them make a change because I’m already on a seasonal service and upgrades and downgrades are not allowed.  I would rather get this resolved, then cancel my entire account. Any help you can provide would be appreciated.