I emailed them (hello@planetcom.co.uk) as recommended and got a response. They do install new batteries, but cannot ship them. So you have to ship your device to them. The cost for a new battery is £75.00 plus P&P, and the cost for shipping from the US (using parcelhero.com) is almost $50. So this will be a very expensive battery repair if I go this route.
If anyone knows of a compatible battery for another phone that is less expensive and doesn't require me to send in my unit, I would love to know about it.