Scale image on material

Hi, how can I scale image on material? Currently I’ve set wrap mode to clamp and used tiling and offset to scale and move image on object, but I’m getting this weird stretching:

change the wrap mode from clamp to repeat, and then try changing x and y tiling value.

Ok, so using modified shader from this anwser I was able to get result I wanted.
Modified shader:

 Shader "Custom/transparent_col" {
     Properties {
         _Color ("Color", Color) = (1,1,1,1)
         _TransparentColor ("Transparent Color", Color) = (1,1,1,1)
         _Threshold ("Threshhold", Float) = 0.1
         _MainTex ("Albedo (RGB)", 2D) = "white" {}
     SubShader {
         Tags { "Queue"="Transparent" "RenderType"="Transparent" }
         LOD 200
         #pragma surface surf Lambert alpha
         sampler2D _MainTex;
         struct Input {
             float2 uv_MainTex;
         fixed4 _Color;
         fixed4 _TransparentColor;
         half _Threshold;
         void surf (Input IN, inout SurfaceOutput o) {
             // Read color from the texture
             half4 c = tex2D (_MainTex, IN.uv_MainTex);
             // Output colour will be the texture color * the vertex colour
             half4 output_col = c * _Color;
             //calculate the difference between the texture color and the transparent color
             //note: we use 'dot' instead of length(transparent_diff) as its faster, and
             //although it'll really give the length squared, its good enough for our purposes!
             half3 transparent_diff = -;
             half transparent_diff_squared = dot(transparent_diff,transparent_diff);
             //if colour is too close to the transparent one, discard it.
             //note: you could do cleverer things like fade out the alpha
             if(transparent_diff_squared < _Threshold)
                 output_col = 1;
             //output albedo and alpha just like a normal shader
             o.Albedo = output_col.rgb;
             o.Alpha = output_col.a;
     FallBack "Diffuse"