Hello Rakibul-
Thanks for reaching out, we’ll do everything we can to help you get your website back.
By default, Total Upkeep stores your backups within your hosting account. Because of that, it’s possible that your backup files may also have been lost when your account was deleted. Total Upkeep does include the ability to store backups on an FTP server. Do you recall configuring remote backups?
If you were using Total Upkeep Premium, you also had the option to set up remote backups on Google Drive, Amazon S3, or DreamHost’s DreamObjects. If you have any of those services, check them for your backup files as well.