Your using a VPS was probably what set off a red flag for Kraken to suspend your account. I originally assumed you used something like TeamViewer to conduct the verification process, but it's generally not an extremely difficult task for exchanges and websites in general to find the details of your IP address and whether or not it's from a datacenter or something of the sort. Kraken's probably very picky about this and so your account was suspended, but I would suggest signing up to another exchange and finishing verification on your home network to avoid any potential issues.