Suffering - No shipment from AGS Frasers, 5 months

I got transferred to Congo from Angola and booked my shipment through AGS Frasers.<br> First of all - they charged 15,000 USD for a small household stuff - way over priced to ship it to the country sharing international borders.<br> The thing to transport were crockeries, toys, cloths - the largest thing was an in-room swing for 1 person (could weight 25 kgs at most).<br> I still booked it as it was a preferred company by my company.<br> The packing were done on 7th of Jan, 2015 with a promise that things will reach Congo in 3-5 weeks.<br> We reached Congo on 1st week of Feb, 2015 with the expectation that by middle/end of Feb we will get the shipment.<br> It is now May - we didn't get our shipment and every time we are asking for a reply, we are getting new excuses.<br> <br> I need some suggestions how we can raise a complaint against them in some international forum or even want to sue them in courts.<br> Your suggestions will be highly appreciated.<br>