I also was facing the same problem yesterday. The support suggested upgrading to the business plan which has unlimited I/O usage and other resources. But when I upgrade to business plan there was issue with the resources. They gave me the same resources as in deluxe plan therefore i had to chat with support team.
After fixing the issue, I again faced the I/O usage problem in business plan. As the support team said, it does not have any restriction of resources but still i was facing the problem .
My ultimate sugesstion is do not use godaddy services. They provide the **bleep**tiest services and their support team do not have any idea what is causing the problem. And their plans say one thing before purchasing and give another services.