Based on service of TAP Portugal you may consider to book an open jaw flights from Europe to Bogota, capital of South American country Colombia. To book the cheapest fare available please look for flights departing from Portugal (Lisbon or Porto) and returning back to main airports in Germany or London. Open jaw tickets on these routes are now starting at €342 or £331. 
If interested in this TAP Portugal promotion please look for flights between November 2015 till end of March 2016. (except black out perioud around Christmas holidays). Max stay 3 months. Booking to be done till 25th of September 2015 or until sold out. Please refer to below booking samples if interested in these open jaw flights to Colombia in South America.
Booking samples
Portugal - Colombia - Germany for €342 or directly with TAP Portugal for €365
Travel date samples
2. - 14.11.
7. - 21.11.
21.11. - 5.12.2015
16. - 30.1.2016
30.1. - 13.2.
8. - 22.2.
29.2. - 14.3.
3. - 21.3.
To check your connection possibilities we recommend to use service of Skyscanner. This tool gives you quickly an idea which airlines are available from your homecity. To book some affordable accommodation you may consider booking agents such as Venere. They are now also offering 8% promotional code for additional discount off hotel rooms. More details to be found here.
Booking sample of cheap TAP Portugal open jaw flights to Colombia from €342/£331 here. In this case you would be departing from Lisbon to Bogota on 21st of november 2015. Your return flight from South America back to Frankfurt in Germany would be on 5th of December 2015.
