Hi, SQ on the ground is not 5*!
I had similar experiences with them when they canceled the SIN -LAX nonstop and I planned to fly straight back home to MUC connecting to LH for late evening flight using a remaining coupon on LH (otherwise expired) .
I spoke to the customers service desk several times but they offered no real solution e.g flying via NRT , SFO or rebook me to Thai etc.
Even the Thai customer service is more helpful!!