I am very sorry to hear of your experience. I can't speak for your previous phone calls but I can help clarify a few things.
We do suggest creating a master template to copy and reuse in your account. This template would be the basics of your design so it will include your standard layout and branding but no content. Every time you need to create a new email you copy that master template so you are starting fresh with your layout. This option works for some users.
Another option if you would rather copy your last email (which is fine!) is to make sure you are replacing the content heavy blocks with fresh ones or using the clear styles button on the toolbar to make sure you are preventing the HTML code from building up in the background. This is what causes some strange text changes when you send your email out. At this time we're putting a big focus on this type of situation to determine the best ways for us to help you avoid it. I'll be sure to share any updates here or in the Community for you.
... View more