Join Date: Aug 2011
Location: Barcelona, London, on a plane
Programs: IB+ Gold, TK E+, Hyatt Globalist, Marriott LTP, IHG Diamond
Posts: 14,184
You can't merge two PNRs into one later.
VS might be able to cancel the return and immediately re-book you as a return ticket if award space is still there or they can hold onto it through the cancellation process. They more likely than not will charge you the change fee.