I work it out as a mid 2:2 - 56.4%. 30 credits at a third class and 30 credits at a 2:2 in third year really bring your average down considerably. The third and 2:2: in second year also brings you down a bit.
(69+65+65+62+55+42)/6 = your second year average, which is 59.6%
(65+53+49)/3 = your third year average, which is 55.3%.
Your overall average is 75% of your third year plus 25% of your second year so: 0.25*(59.6)+0.75(55.3) = 56.4%, hence a 2:2 overall.
Realistically you weren't hitting a 2:1 in either year (in fact most of your modules in third year and half of them in second year were under a 2:1 and the ones that were over weren't high 1sts or anything to balance that out) so you weren't going to be getting a 2:1 overall realistically. Unless the remaining 30 credits of modules in each second and third year are actually higher than what you've listed and so would bring your averages up.