Does Apple offer SSD upgrades? MacBook Pro (Retina, 13-inch, Early 2015)

Hello,

Company I work for made bit of mistake by purchasing pile of these (MacBook Pro, Retina, 13-inch, Early 2015) with 120GB SSD. Eventually we realised that it's not enough for what we do (too late to return / replace).

Does Apple offer upgrades?

Or, alternatively, will we void warranty by upgrading ourselves with this SSD (I understand it's compatible). But we'd probably prefer leaving it to Apple.

Cheers