For the first time I reddemed 840,000 kris miles for 4 business saver awards from SYD to MAD rtrn.

i had to phone the agent to book and couldnt get the itinerary I wanted. I was expecting the total taxes to be around $1000 so $250 per passenger but was quoted $637 per passenger!
Was desperate to secure the flights so paid a total of almost $2600!!

break down per passenger:

Fare: 0.00 SGD
Tax: YR 374.80 SGD
YQ 70.60 SGD
L7 13.80 SGD
OP 6.10 SGD
SG 38.90 SGD
WY 54.80 SGD
WG 4.50 SGD
WG 4.50 SGD
TR 7.90 SGD
JD 24.10 SGD
OG 1.00 SGD
QV 5.50 SGD
RA 30.60 SGD
Total: 637.10 SGD

my Itinerary is as follows

SYD to SIN on SQ, 3 day free stopover.
SIN to MAD via Istanbul on Turkish airlines

rtn
MAD to MUC (economy). MUC to SIN to SYD on SQ

I think I have been over charged because I have checked the same itinerary on a paid ticket and the taxes are no way near what I have paid.

can anyone help??
thanks